Yes, in 5 billion years, nothing you do will matter at all. Probably much sooner than that. 
But, a candle flame doesn't lose its purpose of giving light and heat simply because it is blown out. And I don't lose my purpose of learning, loving, helping, etc simply because I die.
From what I can see, *real* purpose is local: it happens here and now. To worry about a lack of 'ultimate' purpose is then simply a mistake: you are missing the good stuff right here and misunderstanding what a 'purpose' really means.
It's always seemed rather egotistical to think that anything I do will have 'ultimate' consequences.
But, a candle flame doesn't lose its purpose of giving light and heat simply because it is blown out. And I don't lose my purpose of learning, loving, helping, etc simply because I die.
From what I can see, *real* purpose is local: it happens here and now. To worry about a lack of 'ultimate' purpose is then simply a mistake: you are missing the good stuff right here and misunderstanding what a 'purpose' really means.
It's always seemed rather egotistical to think that anything I do will have 'ultimate' consequences.
